JP7222160B2 - Electronic component, patch antenna and antenna device comprising the patch antenna - Google Patents

Description

The present invention relates to an electronic component, a patch antenna, and an antenna device including the patch antenna, and more particularly to a surface-mounted electronic component, a patch antenna, and an antenna device in which the patch antenna is surface-mounted on a printed circuit board.

2. Description of the Related Art In recent years, small electronic devices that transmit and receive information to and from other electronic devices through wireless communication have been used in a wide range of fields. Such electronic equipment is equipped with a small antenna device for receiving radio waves, and a dielectric patch antenna has been put into practical use as this type of antenna device.

A dielectric patch antenna includes a ground electrode made of a thin metal film over substantially the entire surface of a dielectric element in which the antenna is built. This dielectric patch antenna is surface-mounted by soldering its ground electrode onto a land of a printed circuit board to form a compact antenna device.

In such a surface mounting technique, first, solder paste is printed on the land of the printed circuit board in advance, and the dielectric patch antenna is placed on the land of the printed circuit board so that the solder paste and the ground electrode are in contact with each other. Then, the solder is once melted by a reflow process and then solidified again, thereby mechanically fixing and electrically connecting the land of the printed circuit board and the ground electrode of the dielectric patch antenna.

In general, when an electronic component is surface-mounted, the electronic component is once held by the surface tension of the solder melted on the land, and the self-alignment effect allows the mounting position of the electronic component to be accurately controlled with respect to the position of the land. You can expect to be able to.

However, the ground electrode made of a metal material is formed on substantially the entire surface of the dielectric element. Such a metal material has a high wettability to solder, and the melted solder spreads over the entire surface of the ground electrode, thereby reducing the holding force due to surface tension. Therefore, after the solder is melted and before it is solidified again, the dielectric patch antenna may move in translation and rotation on the printed circuit board, and may deviate from the predetermined mounting position.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and an object of the present invention is to provide an electronic component having a large-area electrode, that is, a dielectric patch antenna having a large-area ground electrode with high positional accuracy. To provide a technology for surface mounting on a printed circuit board with a low manufacturing cost.

In order to achieve the above object, according to a first aspect of the present invention, an electronic component comprises a substrate having a mounting surface, and an electrode having a substantially rectangular shape disposed on the mounting surface of the substrate. , the electrode has, in the vicinity of each of its four vertices, one slit provided on one side and another slit provided on the other side of the two sides that intersect at the vertices of the rectangular shape, It is characterized by

According to a second aspect of the present invention, in the first aspect, one slit extends inward from one side in a direction substantially orthogonal to the one side, and the other slit extends inward from the other side, It is characterized by extending in a direction substantially perpendicular to the other side.

According to the patch antenna of the third aspect of the present invention, the dielectric element having the first surface and the second surface facing the first surface is arranged on the first surface of the dielectric element. a ground electrode disposed on a second surface of a dielectric element and having a generally rectangular shape; and a signal electrode spaced apart from the ground electrode on the second surface. In the vicinity of each of the four vertices of the ground electrode, of the two sides that intersect at the vertices of the rectangular shape, one slit is provided on one side and another slit is provided on the other side. characterized by having

According to a fourth aspect of the present invention, in the third aspect, one slit extends from one side in a direction substantially perpendicular to the one side, and the other slit extends from the other side to the other side substantially perpendicular to the other side. characterized by extending in the direction of

According to the antenna device of the fifth aspect of the present invention, in the third aspect or the fourth aspect, the ground electrode has a notch on one side, and the signal electrode is arranged in the notch. characterized in that

According to a sixth aspect of the present invention, the patch antenna of any one aspect from the third aspect to the fifth aspect and four lands having one surface and each having a generally rectangular shape is disposed on one surface of the printed circuit board, the second surface of the dielectric element and the one surface of the printed circuit board face each other, and the vicinity of the four vertices of the ground electrode of the patch antenna is located on the printed circuit board. Each slit is connected to four lands, one slit extends parallel to and adjacent to one side of a corresponding one of the four lands, and the other slit extends in one of the four lands. It is characterized in that it extends parallel to and adjacent to another side perpendicular to one side of the corresponding one land.

According to a seventh aspect of the present invention, in the sixth aspect, in the vicinity of each of the four vertices, the length of one slit is longer than the length of one side of the land adjacent to the slit. The length of the other slit is shorter than the length of the other side of the land adjacent to the other slit.

According to an eighth aspect of the present invention, in the seventh aspect, in the vicinity of each of the four vertices, the length of one slit is the length of one side of the land adjacent to the slit. longer than one-half, and the length of the other slit is longer than one-half of the length of the other side of the land adjacent to the other slit.

According to a ninth aspect of the present invention, in any one of the sixth aspect to the eighth aspect, the ground electrode is connected to each of the four lands of the printed circuit board via solder. characterized in that

According to a tenth aspect of the present invention, in any one of the sixth to ninth aspects, the four lands are arranged on one conductive layer on one surface of the printed circuit board. defined by four openings in the solder resist.

According to an eleventh aspect of the present invention, in any one of the sixth to tenth aspects, each of the four lands is a square.

According to a twelfth aspect of the present invention, in any one of the sixth to eleventh aspects, the outer shape of the ground electrode is square.

According to a thirteenth aspect of the present invention, in any one of the sixth aspect to the twelfth aspect, the printed circuit board has a , a rectangular-shaped further land aligned with the two lands, the ground electrode comprising a further slit extending parallel to and adjacent to one side of the further land, and the further land and another slit extending parallel to and adjacent to one side of and the other side facing each other.

According to a fourteenth aspect of the present invention, in any one aspect from the sixth aspect to the thirteenth aspect, the and a signal land connected to the signal electrode, wherein the signal electrode is connected to the signal land.

According to the electronic component, the patch antenna, and the antenna device comprising the patch antenna of the present invention, by preventing molten solder from spreading over a wide range along the ground electrode, the holding force due to surface tension is maintained and the self- Alignment effect is obtained.

Therefore, it is possible to provide a technology for surface-mounting an electronic component having a large-area electrode, that is, a dielectric patch antenna having a large-area ground electrode, on a printed circuit board with high positional accuracy at low manufacturing cost.

FIG. 1 is a perspective view of a patch antenna according to one embodiment. FIG. 2 is a plan view of the ground electrode of the patch antenna of one embodiment. FIG. 3 is an exploded view of the antenna device of one embodiment. FIG. 4 is a perspective view of the antenna device in which the patch antenna of one embodiment is seen through.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a patch antenna 1 according to one embodiment. The patch antenna 1 includes a dielectric element 2 having a substantially flat rectangular parallelepiped shape, and has an antenna pattern (not shown in the figure) for receiving radio waves therein.

The patch antenna 1 is, for example, an electronic component for surface mounting, and a dielectric element 2 forming a base thereof has a first surface 2a and a second surface 2a forming a flat rectangular parallelepiped upper surface and a lower surface facing each other. and a surface 2b of A radiation electrode 3 is arranged on the first surface 2a, and a ground electrode 6 and a signal electrode 4 are arranged on the second surface. The ground electrode 6 and the signal electrode 4 are separated from each other, and the ground electrode 6 covers substantially the entire second surface 2b except for the signal electrode 4 and its vicinity.

FIG. 2 is a plan view of the ground electrode 6 of the patch antenna 1 of one embodiment. The ground electrode 6 has a substantially rectangular outer shape. Its outline may be, for example, square. In the vicinity of one vertex 6c of the outer shape of the ground electrode 6, one slit 6a provided on one side and another slit 6a provided on the other side of the two sides intersecting at the vertex 6c are provided. It is

One slit 6a extends inward from one side of the outer shape of the ground electrode 6 so as to cut the ground electrode 6 in a direction substantially orthogonal to the one side. Another slit 6a extends inward from the other side of the outer shape of the ground electrode 6 so as to cut the ground electrode 6 in a direction substantially perpendicular to the other side.

Similarly, in the vicinity of each of the other three vertices 6c, one slit 6a and another slit 6a extend inward from each corresponding side in a direction substantially perpendicular to the respective side. It extends so that 6 is notched.

Between the two slits 6a provided on one side connecting two vertices 6c adjacent to each other, a slit extending inward from the one side of the outer shape of the ground electrode 6 is substantially orthogonal to the one side. A further slit 6b may be provided which extends so as to cut through the ground electrode 6 in the direction of .

Furthermore, between the two slits 6a provided on the other side connecting the other two vertices 6c adjacent to each other, the ground electrode 6 is formed with a concave portion extending inward from the other side of the outer shape of the ground electrode 6. A recessed cutout 5 is provided, and the signal electrode 4 is arranged inside the cutout 5 .

The ground electrode 6 is made of a conductive material, and may be a thin film containing silver as a main component, for example. This thin film containing silver as a main component can be obtained by screen-printing a silver paste in a predetermined pattern on the second surface 2b of the dielectric element 2 and sintering the printed silver paste by heat treatment at a high temperature. .

Screen printing can be carried out using a screen that is produced by hardening areas not required for printing with an emulsion or the like so that the silver paste does not permeate. For example, a screen for transferring the pattern of the ground electrode 6 is placed on the second surface 2b of the dielectric element 2, and silver paste is placed on the screen. Then, by sliding the squeegee on the screen, the silver paste passes through the screen and is printed on the second surface 2b of the dielectric element 2 in a pattern previously drawn on the screen.

As a material for the screen, fibers such as nylon, or woven wire made of thin metal such as stainless steel can be used. Since the screen can be easily produced by only hardening the unnecessary positions for printing with emulsion, etc., the pattern of the ground electrode 6 having the slit 6a and the notch 5 and the signal electrode 4 arranged inside the notch 5 The whole thing can be drawn on one screen.

Next, an antenna device 20 configured by mounting the patch antenna 1 on the printed circuit board 10 will be described. FIG. 3 shows an exploded view of the antenna device 20 comprising the patch antenna 1 and the printed circuit board 10. As shown in FIG.

A signal land 12 connected to the signal electrode 4 of the patch antenna 1 and four lands 14 connected to the vicinity of four vertexes of the ground electrode 6 are arranged on one surface 11 of the printed circuit board 10 . The printed circuit board 10 may have a multilayer wiring structure in which substrates made of an insulating material and conductive layers are alternately laminated in multiple layers. The signal land 12 and each of the four lands are preferably formed in the uppermost wiring layer of the multilayer wiring.

The signal land 12 is electrically connected to a wiring for transmitting a signal output from the patch antenna 1 inside the printed circuit board 10 . Each of the four lands 14 is electrically connected to a ground wiring layer defining a ground potential inside the printed board 10 . The signal land 12 and each of the four lands are electrically isolated from each other.

In principle, one land 14 may be connected to the ground electrode 6, but in order to make the ground potential of the patch antenna 1 more stable, a land 14 may be connected between the ground electrode 6 and the ground wiring layer of the printed circuit board 10. It is required to reduce the series resistance of the ground electrode 6 as much as possible and to minimize the effect of the series resistance distributed in the planar direction of the ground electrode 6 . For that purpose, it is preferable to provide at least four lands 14 and connect them to the vicinity of the four vertexes 6c of the ground electrode 6, respectively.

In addition, a large-area conductive layer is provided on the uppermost wiring layer of the printed circuit board 10 so as to cover the entire area where the four lands 14 are to be arranged, and the surface of the large-area conductive layer is covered with a solder resist. Alternatively, four lands 14 may be provided by providing four openings at predetermined positions on the conductive layer.

Additionally, printed circuit board 10 may include additional lands 14b and center lands 14c. For example, the additional land 14b may be arranged between two adjacent lands of the four lands 14 . Also, the central land 14 c may be arranged at a position connectable to the vicinity of the center of the ground electrode 6 . These added additional lands 14b and center lands 14c contribute to further stabilization of the ground potential of patch antenna 1 described above.

FIG. 4 shows an antenna device 20 configured by mounting the patch antenna 1 of one embodiment on a printed circuit board 10 . The second surface 2b, which is the mounting surface of the dielectric element 2 of the patch antenna 1, and the one surface 11 of the printed circuit board 10 are placed so as to face each other.

The ground electrode 6 of the patch antenna 1, the land 14, the further land 14b, and the center land 14c are mechanically fixed through the solder by melting the solder paste by reflow treatment and solidifying it again. It is mounted by surface mount technology to electrically connect together. The signal electrode 4 and the signal land 12 are also connected in the same step as the ground electrode 6 at the same time.

When the patch antenna 1 is mounted on the printed circuit board 10, one slit 6a is adjacent to and parallel to one side of the land 14 in the vicinity of one of the four vertices 6c of the ground electrode 6. , and the other slit 6a extends parallel to and adjacent to another side perpendicular to one side of the land 14. As shown in FIG.

The paste solder printed on the land 14 is melted in a reflow process, which is one step in the procedure for surface-mounting the patch antenna 1 on the printed circuit board 10 . The melted solder is held within the area of each land 14 on the printed circuit board 10 side, and tries to move along the surface of the ground electrode 6 on the patch antenna 1 side. However, the movement of the solder along the surface of the ground electrode 6 is stopped by one slit 6a and the other slit 6a, and the extent to which the solder spreads is defined by the positions of those slits 6a.

As a result, the positional relationship between the ground electrode 6 and the land 14 is such that one slit 6a is adjacent to one side of the land 14 in parallel, and the other slit 6a is perpendicular to one side of the land 14. Alignment is achieved by the self-alignment effect caused by the surface tension of the melted solder so as to be parallel and adjacent to the other side.

This self-alignment effect becomes more conspicuous by arranging one slit 6a and another slit 6a near each of the four vertices 6c of the ground electrode 6. FIG. Further, when the rectangular outer shape of the ground electrode 6 is substantially square, a uniform self-alignment effect can be obtained in each of the front, rear, left, right, and rotational directions, which is more preferable.

The self-alignment effect is maximized when the lengths of one slit 6a and the other slit 6a match the lengths of the sides of the land 14. FIG. However, if the slit 6a is extended to match the length of each side of the land 14, the portion near the vertex 6c of the ground electrode 6 is separated from the central portion of the ground electrode 6, and the ground electrode 6 becomes essential function is impaired.

Therefore, the apex 6c is formed so that the portion in the vicinity of the apex 6c is not separated, that is, to the extent that an adverse effect due to an increase in electrical resistance between the portion in the vicinity of the apex 6c and the central portion of the ground electrode 6 does not become apparent. It is necessary to secure the width of the ground electrode 6 that connects the nearby portion and the central portion. Therefore, it is essential that the length of each of the slits 6a and the other slits 6a is shorter than the length of each side of the land 14. FIG.

On the other hand, when the molten solder is held on the rectangular land 14, the force that causes the solder to expand in the lateral direction increases near the midpoint of each side of the land 14. As shown in FIG. Therefore, in order to suppress the lateral spread of the melted solder along the surface of the ground electrode 6 and obtain the self-alignment effect, each length of one slit 6a and the other slit 6a should be at least land length. It is necessary to make it 1/2 or more of the length of each of the 14 sides.

Further, when the shape of the land 14 is square, the self-alignment effect due to the surface tension becomes uniform in the directions of the four sides of the land 14, which is more preferable.

When a further land 14b is arranged between two lands 14 adjacent to each other on the printed circuit board 10 so as to be aligned with the two lands 14, the ground electrode 6 is provided with one of the further lands 14b. One further slit 6b extending parallel and adjacent to the side and another further slit 6b extending parallel and adjacent to one side of the further land 14b and the other side facing each other are arranged. may be

Here, it is preferable that connection between the signal electrode 4 of the patch antenna 1 and the signal land 12 is also performed at the same time as the mounting process for connecting the ground electrode 6 and the land 14 by solder reflow. By performing the alignment at the same time, the alignment accuracy between the signal electrode 4 and the signal land 12 is also improved due to the effect of self-alignment between the ground electrode 6 and the land 14 .

As described above, according to the electronic component, the patch antenna, and the antenna device including the patch antenna of the present invention, the molten solder is prevented from spreading over a wide range along the ground electrode, and the holding force due to the surface tension is reduced. is maintained, and a self-alignment effect is obtained.

Therefore, it is possible to provide a technology for surface-mounting an electronic component having a large-area electrode, that is, a dielectric patch antenna having a large-area ground electrode, on a printed circuit board with high positional accuracy at low manufacturing cost.

REFERENCE SIGNS LIST 1 patch antenna 2 dielectric element 2a first surface 2b second surface 3 radiation electrode 4 signal electrode 5 notch 6 ground electrode 6a slit 6b further slit 6c vertex 10 printed circuit board 11 one surface 12 signal land 14 land 14b further land 15 side of land 20 antenna device

Claims (12)

a dielectric element having a first surface and a second surface facing the first surface;
a radiation electrode disposed on the first surface of the dielectric element;
a ground electrode having a substantially rectangular shape disposed so as to cover substantially the entire second surface of the dielectric element;
A patch antenna comprising a signal electrode spaced apart from the ground electrode on the second surface,
The ground electrode is provided in the vicinity of each of the four vertices so as to extend inward from one of the two sides that intersect at the vertices of the rectangular shape so as to cut out the electrode. having one slit and another slit extending inwardly from the other side so as to cut out the electrode ,
A patch antenna according to claim 1, wherein any one side of the ground electrode has a cutout portion recessed inwardly from the side to form a concave portion, and the signal electrode is arranged in the cutout portion. 2. The slit according to claim 1, wherein said one slit extends from said one side in a direction substantially perpendicular to said one side, and said other slit extends from said other side in a direction substantially perpendicular to said other side. patch antenna. a dielectric element having a first surface and a second surface facing the first surface;
a radiation electrode disposed on the first surface of the dielectric element;
a ground electrode disposed on the second surface of the dielectric element and having a generally rectangular shape;
A patch antenna comprising a signal electrode spaced apart from the ground electrode on the second surface,
The ground electrode has, in the vicinity of each of its four vertices, one slit provided on one side and another slit provided on the other side of the two sides that intersect at the vertices of the rectangular shape. , a patch antenna , and
a printed circuit board having a surface and having four generally rectangular lands disposed on the surface;
the second surface of the dielectric element and the one surface of the printed circuit board face each other, and the vicinity of the four vertices of the ground electrode of the patch antenna are connected to the four lands of the printed circuit board, connected to each
The one slit extends parallel to and adjacent to one side of one corresponding land out of the four lands, and the other slit extends in parallel to one corresponding land out of the four lands. extending parallel to and adjacent to another side perpendicular to said one side of
In the vicinity of each of the four vertices,
The length of the one slit is shorter than the length of the one side of the land adjacent to the one slit, and the length of the other slit is the other side of the land adjacent to the other slit. An antenna device that is shorter than the length of the 4. The method according to claim 3, wherein said one slit extends from said one side in a direction substantially perpendicular to said one side, and said other slit extends from said other side in a direction substantially perpendicular to said other side. patch antenna. 5. The patch antenna according to claim 3, wherein said ground electrode has a notch on one side thereof, and said signal electrode is arranged in said notch. In the vicinity of each of the four vertices,
The length of the one slit is longer than half the length of the one side of the land adjacent to the one slit, and the length of the other slit is greater than the length of the side of the land adjacent to the other slit. 6. Antenna device according to any one of claims 3 to 5 , longer than half the length of said other side of the land. 7. The antenna device according to any one of claims 3 to 6 , wherein said ground electrode is connected to each of said four lands of said printed circuit board via solder. The antenna device according to any one of claims 3 to 7, wherein said four lands are defined by four openings of a solder resist arranged on one conductive layer of said one surface of said printed circuit board. . 9. Antenna device according to any one of claims 3 to 8 , wherein each of said four lands consists of a square. 10. The antenna device according to any one of claims 3 to 9 , wherein the ground electrode has a square profile. The printed circuit board includes an additional rectangular land arranged between two lands adjacent to each other among the four lands and aligned with the two lands,
The ground electrode has a further slit extending parallel to and adjacent to one side of the further land and another side of the further land that is adjacent to and parallel to the one side of the further land. 11. Antenna device according to any one of claims 3 to 10 , comprising a further slit extending into the . further comprising a signal land disposed on the one surface of the printed circuit board and electrically isolated from any of the four lands;
The antenna device according to any one of claims 3 to 11 , wherein said signal electrode is connected to said signal land.

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